Pakistan has evacuated hundreds of citizens and diplomatic staff from war-torn Yemen.

Reports said a Pakistan International Airlines Boeing 747 took off from Yemen's Al-Hudaydah airport on March 29 with 494 Pakistani nationals on board.

The Saudi military said operations around the Red Sea port of Al-Hudaydah stopped for more than two hours to allow the evacuation.

Meanwhile, the Pakistani navy said one of its frigates left for the Gulf of Aden. Islamabad says about 3,000 Pakistani citizens live in Yemen.

Pakistani Prime Minister Nawaz Sharif has rejected reports that the country would join a Saudi-led campaign of air strikes targeting Shi'ite rebels, known as Huthis, who have taken control of much of Yemen.

Pakistan is a longstanding ally of Saudi Arabia, which accuses Shi'ite-led Iran of backing the Huthi fighters.